135 research outputs found

    Constraining pre Big-Bang-Nucleosynthesis Expansion using Cosmic Antiprotons

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    A host of dark energy models and non-standard cosmologies predict an enhanced Hubble rate in the early Universe: perfectly viable models, which satisfy Big Bang Nucleosynthesis (BBN), cosmic microwave background and general relativity tests, may nevertheless lead to enhancements of the Hubble rate up to many orders of magnitude. In this paper we show that strong bounds on the pre-BBN evolution of the Universe may be derived, under the assumption that dark matter is a thermal relic, by combining the dark matter relic density bound with constraints coming from the production of cosmic-ray antiprotons by dark matter annihilation in the Galaxy. The limits we derive can be sizable and apply to the Hubble rate around the temperature of dark matter decoupling. For dark matter masses lighter than 100 GeV, the bound on the Hubble-rate enhancement ranges from a factor of a few to a factor of 30, depending on the actual cosmological model, while for a mass of 500 GeV the bound falls in the range 50-500. Uncertainties in the derivation of the bounds and situations where the bounds become looser are discussed. We finally discuss how these limits apply to some specific realizations of non-standard cosmologies: a scalar-tensor gravity model, kination models and a Randall-Sundrum D-brane model.Comment: 19 pages, 15 figures, LaTex, uses revtex

    Temporary hair loss after injection of hyaluronic acid filler

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    BACKGROUND: Compromised blood flow after filler injection is generally thought to result from intra‐arterial obstruction. AIMS: To test this hypothesis. PATIENT: A case presented with the clinical picture of reduced arterial blood flow after hyaluronic acid filler injection in the temporal region and subsequent hair loss. METHOD: Clinical and ultrasound (US) assessments as well as ultrasound guided hyaluronidase injection were performed. RESULT: Blood flow was restored and hair loss proved to be temporary. CONCLUSION: There are many arguments to conclude that the problem did not result from intra‐arterial occlusion, but rather from outside compression of the artery

    Enlarging mSUGRA parameter space by decreasing pre-BBN Hubble rate in Scalar-Tensor Cosmologies

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    We determine under what conditions Scalar Tensor cosmologies predict an expansion rate which is reduced as compared to the standard General Relativity case. We show that ST theories with a single matter sector typically predict an enchanced Hubble rate in the past, as a consequence of the requirement of an attractive fixed point towards General Relativity at late times. Instead, when additional matter sectors with different conformal factors are added, the late time convergence to General Relativity is mantained and at the same time a reduced expansion rate in the past can be driven. For suitable choices of the parameters which govern the scalar field evolution, a sizeable reduction (up to about 2 orders of magnitude) of the Hubble rate prior to Big Bang Nucleosynthesis can be obtained. We then discuss the impact of these cosmological models on the relic abundance of dark matter is minimal Supergravity models: we show that the cosmologically allowed regions in parameter space are significantly enlarged, implying a change in the potential reach of LHC on the neutralino phenomenology.Comment: 10 pages, 7 figure

    Reticulated livedoid skin patterns after soft-tissue filler–related vascular adverse events

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    Background: For the treatment of vascular adverse events caused by filler injections, duplex ultrasound imaging may be used. The findings of duplex ultrasound examination and the clinical features of reticulated livedoid skin patterns were compared with the hemifaces anatomy. Objective: The objective of this study was to link the reticulated livedoid skin patterns to the corresponding duplex ultrasound findings and the facial perforasomes. Methods: Duplex ultrasound imaging was used for the diagnosis and treatment of vascular adverse events. The clinical features and duplex ultrasound findings of 125 patients were investigated. Six cadaver hemifaces were examined to compare the typical livedo skin patterns with the vasculature of the face. Results: Clinically, the affected skin showed a similar reticulated pattern in each facial area corresponding with arterial anatomy and their perforators in the cadaver hemifaces. With duplex ultrasound, a disturbed microvascularization in the superficial fatty layer was visualized. After hyaluronidase injection, clinical improvement of the skin pattern was seen. Normalization of blood flow was noted accompanied by restoration of flow in the corresponding perforator artery. The skin patterns could be linked to the perforators of the superficial fat compartments. Conclusion: The livedo skin patterns seen in vascular adverse events may reflect the involvement of the perforators.</p

    Treating facial overfilled syndrome with impaired facial expression—Presenting clinical experience with ultrasound imaging

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    Background: Facial overfilled syndrome is an adverse event following minimally invasive soft tissue filler injections. It presents in most cases as excess midfacial volume and/or as unnatural smile which is difficult to detect due to the absence of standardized evaluation methods. Objective: To showcase how to identify, evaluate, and treat facial overfilled syndrome by utilizing facial ultrasound and simultaneous hyaluronidase injections. Methods: Twenty-eight consecutive patients (26 females, 2 males) were enrolled in this study in which facial ultrasound was performed to evaluate the location previously implanted filler material. The position of the oral commissure was objectively measured in relation to bony landmarks, and the severity of lateral canthal lines was assessed by independent and blinded raters. Results: The material was identified in 35.7% inside the subdermal fatty layer, in 28.6% inside the deep supra-periosteal fatty layer, in 10.7% inside the fibrous layer deep to the subdermal fatty layer, whereas in 25.0%, the product was not possible to locate clearly inside one specific layer. On average, 81.6 I.U. [range: 75–150] of hyaluronidase were injected. Lateral canthal line severity was before the treatment 2.28 (1.4) and was after the hyaluronidase treatment 2.02 (1.3) with p = 0.578. The position of the oral commissure increased by 0.60 cm in vertical and by 0.30 cm in horizontal directions (both p &lt; 0.001).Conclusion:Facial overfilled syndrome following aesthetic soft tissue filler injections can present as excess midfacial volume but also as unnatural smile. Targeted hyaluronidase injections into the culprit pockets inside the midfacial soft tissues have shown to re-establish a natural smile, to reduce excess midfacial volume, and to decrease lateral canthal line severity.</p

    Reticulated livedoid skin patterns after soft-tissue filler–related vascular adverse events

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    Background: For the treatment of vascular adverse events caused by filler injections, duplex ultrasound imaging may be used. The findings of duplex ultrasound examination and the clinical features of reticulated livedoid skin patterns were compared with the hemifaces anatomy. Objective: The objective of this study was to link the reticulated livedoid skin patterns to the corresponding duplex ultrasound findings and the facial perforasomes. Methods: Duplex ultrasound imaging was used for the diagnosis and treatment of vascular adverse events. The clinical features and duplex ultrasound findings of 125 patients were investigated. Six cadaver hemifaces were examined to compare the typical livedo skin patterns with the vasculature of the face. Results: Clinically, the affected skin showed a similar reticulated pattern in each facial area corresponding with arterial anatomy and their perforators in the cadaver hemifaces. With duplex ultrasound, a disturbed microvascularization in the superficial fatty layer was visualized. After hyaluronidase injection, clinical improvement of the skin pattern was seen. Normalization of blood flow was noted accompanied by restoration of flow in the corresponding perforator artery. The skin patterns could be linked to the perforators of the superficial fat compartments. Conclusion: The livedo skin patterns seen in vascular adverse events may reflect the involvement of the perforators.</p

    Ultrasound to improve the safety of hyaluronic acid filler treatments

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    Background: Hyaluronic acid fillers are known for a reliable safety profile, but complications do occur, even serious vascular adverse events. Objective: To improve the safety of hyaluronic acid filler treatments. Methods: Ultrasound is used to image hyaluronic acid fillers. Results: Before a filler treatment is performed with ultrasound, previous filler treatments can be brought in to sight and vascular mapping can be performed. In case of adverse events, the filler and the surrounding tissues are visible. Dislocation, abscesses, and vascular adverse events can be seen. Under ultrasound guidance, hyaluronidase can be injected directly into the filler deposit. Conclusion: Ultrasound examination can be an important tool to improve the safety of hyaluronic acid filler treatments
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